Analysis of Im-SH self-assembled monolayer formation and its interaction with Fe2+ and Zn2+ using quartz chemical analyzer

A self-assembly process and dynamic property changes of N-[2-(4-imidazolyl)ethyl]11-mercaptoundecanamide (Im-SH) on gold electrode have been investigated measuring the resonant and electrochemical parameters of quartz crystal using a quartz chemical analyzer and an impedance analyzer. The morphological changes on gold surface have also been investigated using an optical microscopy and a STM. The affinity differences of assembled film for Zn2+ and Fe2+ have also been investigated by the electrochemical experiments. As a result, a two-step process is found in the self-assembly by utilizing abundant analytical variables from the impedance analyzer and a molecular level conformational change has been detected in the scanning tunneling microscopy (STM) images for the self-assembled monolayer (SAM) film and the metal ions bonded film. The conformational change is well corresponding to the electrochemical results.